Production of fuel, etc.



lune 30, 193 s. P. MILLER PRODUCTION OF FUEL, ETC

3 Sheets-Sheet l Fild April 17, 1928 uaraapuq Jaw/7,000]

I i:NVENTOR BY p I W W ATTORNEYS June 30, .1931.

s. P. MILLER RODUCTION 0F FUEL, ETC

Filed April 1'7, 1928 3 Sheets-Sheet 2 (a/re Oren:

Y F .z '9: i

24 000, 0009a. Tar

fllimWed/h mr/ E65Q000 g y; MM 4900, 000ya/s.

I ammoo 5M. P.

A490 fed Fae/0m .ffar'aye fan/f 0,06 #641 Far/7a: e

INVENTOR 61W P. m

ATTORNEYS Patented June 30, 1931 UNITED STATES PATENT ()FFlCil STUART PARMELEE MILLER, OF ENGLEWOOD, NEW JERSEY, ASSIGNOR TO THE BARRETT COMPANY, OF NEW YORK, 11'. Y., A CORPORATIGN OF NEW JERSEY PRODUCTION OF FUEL, ETC.

Application filed April 17,

This invention relates to the production of fuel-from coke oven tar for use in steel mills,

together with the production of creosote oil or creosoting compositions from such coke oven tar.

Where coke oven plants are operated by I steel companies, the coke produced at the coke oven plant is commonly used in the blast furnaces of the steel company and the tar produced at the coke'oven plant is commonly used as fuel in the steel mill, particularly as fuel in open hearth or other furnaces. When i a surplus of tar is produced by the coke oven plant, in excess of that required as fuel in the steel mills, theexcess is commonly sold as tar and is shipped to tar distillation plants and there distilled for the production of distillate oils and pitch. The distillate oils have considerably greater'value than the tar itself, but the pitch has relatively much less value and in some cases presents a problem in its disposal.

The present invention provides an improved process in which surplus tar produced at the coke oven plant is employed for giving distillate oils, and particularly creosote oils, of considerably greater value than the tar, without producing a separate pitch product presenting any problems for its disposition, and in which the pitch produced by the distillation, is blended with tar to give an improved fuel for use in open hearth and other furnaces. The improved process of the present'invention enables the entire surplus production of tar to be converted into valuable distillate oils, such as creosote oil, or coal tar solutions, While providing an improved fuel for use in the operation of the tion with the tar which is not subjected to 1928. Serial No. 2'?0,625.

distillation, thereby producing an improved fuel in the form of a pitch of relatively low melting point which is employed instead of tar as the fuel in the open hearth or other furnaces. By combining these operations at the coke oven plant, the surplus tar production is converted into products of considerably greater value, while the tar ordinarily employed as fuel is replaced in whole or in part by an improved fuel made up of the undistilled tar, or a suitable portion of it, blended with the pitch residue from the distillation to form a homogeneous fuel.

The tar which is subjected to distillation, according to the present invention, is the coke oven tar which is available as surplus production at coke oven and steel plants where only part of the tar is employed as fuel at the steel plants, but instead of distilling only the surplus tar production, I distill a larger amount of tar to give an amount of distillate therefrom which is approximately equal to the surplus tar production volume, and I make up for the part of the tar which would ordinarily be employed as fuel by the pitch residue from the distillation which is approximately equal in volume to that part of the tar distilled which would ordinarily be employed as fuel. It will be understood, however, that these approximate volumes can be varied somewhat, as where only part of the excess tar, not desired as fuel, is subjected to distillation according to the invention.

The distillation of the tar to produce distillate oils and pitch therefrom, can be carried out in ordinary externally heated tar stills, operating either up on successive batches of tar, or continuously. I consider continuous distillation of the tar particularly advantageous since it gives a continuous production. of distillate oils and of pitch residue, which pitch residue can advantageously be blended in a continuous manner with tar to produce an, improved fuel that can be supplied directly to the open hearth or other furnaces as fuel. A. valuable method of carrying out this continuous distillation is in a pipe still in which the tar is heated to a high temperature while being .ly two or more distillates difleringafrom.

1 tiona'llycondensed to give fractions ofdifs- .;.ferent composltion and=bo1hngpo1nt.-

forced at high velocity through a long continuous heating coil and in which theheated tar is discharged into a vapor box orvaporizing chamber to permit separation of vaporized oils from the pitch residue. Such a continuousmethod of distillation-can be carried out in 'stagesto giveffirst a distillate.-

of lower boiling point, and with further distillation of the pitch residue from the first distillation to give pitch of higher'meltingmade a fractional distillation to give directeach other. The distillates can also be frac- The. extent to which the distillation iscar -7 ried can be -varied, bu-t in generalthe dis? :tillation should be carriedsufiicientlyto .pro- ;....duce a distillate oil which can be employed. in whole or in partas creosote. oil, or. for ...ble nding-with tar to make coal tar. solur. f the distillation is carried only to the extent ofpro-Q- tions or creosotin-g compositions.

ducing-pitch "ofharound 1659. F. *melting .point, the totaldistillatesproduced may be,

i a lighter oil.

too light; for certain creosoting purposes v and vmay require fractionation or fractional con.-,

densation to. givea h-eavier creosote oil and tion is carried further to produce a pitch of- Jmelting point around 200 F. or higher,.=and particularly where-.itfis carried to the point: of producing pitch ofmelting point around 250 F. or around 300 F. meltingpoint the.

totaludistillat-e .oil is azvaluable creosote oil,

' a and as much as half or'more of-thetar diss. tilled can be recovered as valuable creosote:

j0il, "leaving a .pitchresidue representing around-half or somewhat less of the The total distillates; produced as above -phenols or tar acids are desired, the; total torecover tar acids therefrom, leaving tar.

solutions,"commonlyimade ofabout 20% of: tar and of creosote oilsj; When the-dis. tillate produced by'thepresent processisemss ployed inmaking such coal tarsolutions an distillatescan be extracted with causticsoda acid free oil which is. a valuable creosote oil.

Insteadof extracting the entire distillate, :the distillate can befractionally condenfed or separated and-only'the lighter ca-rbolic oil subjected to-extraction for the-prodiic-i. 1 -tion of'tar acids-therefrom. In such case, the extracted'oil can he returned-for; blending with the heavier portion of. the distillate..- for use as creosote oil, or can be' -returnedi'. and blendedrwith. pitch or. with tar for use.

as fuel.

Creosote oils are employed toa large. extent in admixture withtar' as so-called'coal tar When, however, the distilla...

tar. sub.- vr jected to distillation.

de--.. scribed can be employed directly as creosote.- oils, and can "be marketed as such; There.

, content. point and a distillate of higher boiling point; In this way, the distillationcan be The pitch residue produced by-the distillationisablended, while still hot with tar to produce an improved fuel to be used in place of tar in the-open hearth or other furnaces. With pitch of melting points around 250 or 600; F. it is important to: carryout the admixture with tar under properly regulated conditions; Unless these; are. observed,--.there is danger of formation ofa-liverymassw To insure an intimate and uniform-admixture and-blending of the hot pitch with the tar, I carry out the admixture with sulficientagi- 'tation to insureyuniform andthorough admixture; This can be accomplished by runningstreams of'the tar and hot pitch together in :a: suitable mixing chamber or tankwith suflicient-a-gitation of the mixture to -insure thorough blending :and homogeneity. The

mixing can thusbe carried out byifiowing the tar. and pitch into a body of the resulting admixture, soathat the gradually and progressively. added tar and pitch blend withjthe accumulated body ofadmixed. material; instead 7 of directly with eachotheri. The-bulk of previously-admixed materials, to which the tar F and: pitch are added. need. not be'large but it should be maintained at a proper'temperature to insure that the added tar and pitch will blend therewith continuously to form ahomogeneous blend. Agitation .duringv the blending operation is important, and aarticula-rly sowhere-the tarand' pitch arerun together directly without-having a body of previously admixed material. to

which the pitch and-tar areadded'. r

:The high temperature of ithe 'li-ot pitch blended with'the cold tar will. give-ablended productswhich has. a; temperature. considerably; above that of the tar anclconsiderably above atmospheric: This is important; be-

cause. the resultingproduct.isitself a pitch :which. may have a melting point considerably above atmospheric temperature, andrvwhich would solidify if permitted to cool toatmospheric temperature; In order to prevent 1 such cooling and solidification, I maintain the blended product at a temperaturewhich' in,- sur'esthat it is'thinly' fluid so that it'can be pumped andhandledandused as fuel in the same equipment in whi'chtar is ordinarily handled for that purpose- The fuel'storage tanks in which;.the;fuel composition of the present inventio-n is-stored should be provided'withqheating means, such as: steam coils in thebottoms'oftheistorage IUD some cases be carried out at a tar distillation tanks, to insure that the fuel product will be maintained thinly fluid. This fuel can then be pumped from the storage tanks to the open hearth or other furnace and there employed in the burners as fuel. It is a more valuable fuel than ordinary coal tar, containing a considerably higher proportion of heavier con- 7 I stituents supplied by the pitch, and being free from a corresponding amount of lighter oil I constituents which have been distilled from the pitch beforeit is blended with the tar to make the new composite fuel product.

, Should it be necessary to store the fuel composition before use, or to discontinue its use temporarily, it can be maintamed in a warm or hot thinly fluid condition by supplying heat to the storage tanks, and it can be kept from solidifying in the pipe lines leading to i the burners by maintaining a continuous circulation of the fuel through these lines and back to the storagetanks so that the circulating fuel will be kept at a temperaure above that of solidification. I I

The excess tar which is available for distillation, according to the present invention,

will vary with different coke oven and steel plants. It may be only a small proportion of v I the total tar produced, or it may be a major ordinarily be considered excess tar.

' er value of the fuel composition produced by blending the pitch residue from the distillation with the undistilled tar make it profitable to distill the greater part-of the tar produced at the coke oven plant, leaving only enough tar undistilled to blend with the pitch residue from the distillation to produce fuel pitch; and if the amount of fuel pitch so produced does not meet the requirements of the steel mill, additional fuel oil can be supplied to make up the fuel requirements of the steel mill. For example, as much as twothirds or more of the total tar produced can be subjected to distillation to give a yield of 50% or more of the tar distilled as valuable distillate oils, and the pitch residue from the distillation can then be blended with the undistilled tar to give a quantity of fuel pitch which may represent only two-thirds or one half or less of the volume of tar produced, in which case the yield of valuable distillate oils may amount to a third or a half or more of the total tar production.

The distillation of the excess tar may in plant .to which the tar is shipped and from which the pitch is returned. In such case, the pitch, if returned in a cold solidified state, will require reheating to make it hot and thinly fluid before it is blended with the undistilled tar to produce the fuel composition. In such case, the fuel composition when produced should be kept hot, or, if permitted to cool and solidify, should be reheated, before it is supplied as fuel at the steel plant, so that it will be supplied to the burners in a hot and thinly fluid condition.

The process of the present invention can be carried out much more advantageously by distilling the excess tar at the place of production or use so that the still hot and thinly fluid pitch residue from the distillation can be blended directly with the undistilled tar to give ahot and thinly fluid fuel composition. If this fuel is permitted to cool and solidify, it must be reheated and rendered thinly fluid before being used as fuel at the steel plant. This need of reheating is eliminated where the distillation and production of the fuel pitch is carried out at the steel plant so that the hot fuel can be produced and used while in a still hot condition and maintained hot and thinly fluid from the time it is produced until it is employed as fuel at the steel plant.

In all cases it is important that the fuel composition be maintained hot and thinly fluid while it is being used as fuel, and, with fuel compositions that solidify when permitted to cool, it is important to supply the fuel compositions in insulated lines to the burners and to maintain a circulation of the fuel continually, as by circulating it past the burners and back to the supply tank and keeping it hot and thinly fluid during circulation, thereby insuring against solidification and freezing of the fuel in the supply pipes, and enabling the fuel composition to be available at all times in a hot and thinly fluid state for use in the fuel burners.

The invention will be further illustrated by the following more detailed description of certain examples thereof, in connection with the accompanying drawings which show illustrative flow sheets and a diagrammatic arrangement of apparatus for the carrying out of the process of the invention and the production of the new fuel composition.

In the accompanying drawings,

Fig. 1 shows a diagrammatic arrangement of apparatus for carrying out the process of the invention; and

Figs. 2 and 3 show illustrative flow sheets.

In the apparatus of Fig. 1 a coke oven block is shown conventionally at 1, having the usual uptake pipes 2 leading from the individual coke ovens to collector main. 3 common to a number of the ovens of the block. In the collector main the coke oven gases are cooled, as by the introduction of ammonia liquor, or ammonia liquor' and tar, an*d "a considerable part, usually the greaterpart, I

- of the tar c-ontainedin the gases is separated @r or condensed. The -tar 'and ammoma [liquoriflow from the collector main to the- -separators or decanters 4e" from"wh1ch the Y ammonia liquoris separately draw'n off at 5, i anolthe tar separately drawn off at 6 to the .tar storage tanks 7.

uThegases from the collectormain pass through the crossover main 8 to the condensers, of which twoare shown as 9 and 9a,

and the gases-then go to the gashandling I system (not shown).

the condensers may be collected together 1n The tarry oils from the separator or decanter 10, the'ammonia 'liquor' drawn off at 11 and the' tarry oilor,

- light tar drawn ofi tanks 30. 7 7 r -The-stillshown is a pipe coil still 13 Dstorage tank by means of thepump i l." A cvapor hox or vapor separating chamber 15 V --is located-at the end of the first heating coil. The pitch collecting in the bottom of thevapor =separating chamber is pumped by pump 116- through-a second heating; coil 17 I and'further heated and discharged into theat 12 to the tar storage through'which the tar is pumped from a tar I vapor separatingchamber'18 from which the pitch residue is drawn oif through the'line .19 to the mixing chamberQO. The heating;

' 1 coils are enclosed in a suitable furnace, heated by any suitable fuel.

? The still illustrated subjects the tar to distillationin two stages, with separation of the distillate oil vapors from the first stageand I further heating of the pitch residue from the first stage to a higher temperature-to produce therefrom a pitch residue of higher melting *point and a heavier distillate. Separate con densers 21 and 22 are provided for ;con-

.dcnsingtm clistillat'es-from'tl1e two stages of distillation, and, if desired,the condensersmaybe fractional condensers, to give heavier and lighter oil distillates. The total distillate can be blended together to give creosote oil, or-part of the oil, particularly the lower; boiling fraction, may be extractedfor tar acids and the neutral oil returned for adiniX-f ture with the unextracted oil to give creosote oil, or employed for other purposes.

' therewith instead of directly with each other,- although, with suiilcient agitation, they may be blended directly with each other without Part of the tar from'the tar storage tank' is pumped by pum'p'23 to themixing chamber and is there intimately admixed with the 7 hot pitch. A suitable agitating device 24 is provided in the mixing chamber for insuring thorough and uniform intermixture. -The" mixing chamber shown is one in which a small body of the mixed material maintained so that the tar and pitch can blend interpositionof a body of the previously blended materiall From the mixing cham her the resulting homogeneous mixture flows while still'warm or hot to'the storage tank 25 from which iris drawn ofi by means of pump 26 throughthe line 27 to the open hearth or other furnace 28 where itis einploye'das fuel.

Figs: 2 and 3 show illustrative fiow'sh-eets giving. typical operations of the "process where the excess tar productionfnot desired 'as fuel, is only around a-quarteror' a} fifth of the total tar production I Assuming,- for example, a total tar production oftwentymillion gallons 'a year of which only" 'aroimd three-quarters is required as fuel and around a quarter is excess production to be used for other-purposes, this'excess productionwould ordinarily be sold as tar,- 'and,'on distillation, according to common methods of distillation,"would give around half orsomewhat 1 more of its volume of creosote oil and around half or s-omewhat'less its volume ofpitch, and this pitch; beinga product/of relatively little value, 'much' less than the value of-the tar itself as fuel, would-fli'mit the r'eturn t'o the tar distiller of the products of-thedistilla- *tionl- Taking the amount 'of tar illustrated in the flow sheets,"na mely, twenty million gal- 1 ions production. with around four and a half million gallons excess over and above-that required for fuel, this excess tar, on distillation, would give around two and a qna'rter mrllion gallons of creosote 011, or something more,

and a somewhat -smalle'r amount of "pitch having a much less valuethan the tar itself as fuel. 7

"According to the present invention, a much larger amount of tar is subj ected to distillationtha'n the excess tar not desired asfue'I, so --that the? amount of creosote oil o-btainable therefrom is approximatelyequal tc'r what would otherwise be the total tarpro' duction.

l/Vhen, instead of creosote o-il,-coal-tar'jsolu-' total of around four and-a halfjmi llion gallons of valuablecoaltar solution.

;The*pitch'produced in the present process 5 is'blende'd' with'thetarwhich isi-not subjected to distillation andnot usedforinaking coal tar solutions to givea tot-al'blended product approximately equal in volume to the "normal fuel requirements of tar in'the' ste'el plant.

When it is appreciated that the value of creosote oil or of coal tar'solutionf isordinarily considerably "more than twice that of thetar' itself,and that pitch has'a' valuewhich represents only a: small "fraction of ithe value of the tar for equal volume, 'and when it is considered that the presentinventionmakes duction'at coke oven andsteel plants. The

pitch, which would ordinarily be a product of little value, is retained as a product having as great or greater a value than the tar itself as fuel, and is .blended with tar to give an improved fuel for open hearth furnaces The carrying out of the process at the coke oven and steel plants eliminates cost of transportation to the tar distillation plant and reduces losses of tar through handling and transportation. f I It will be understood that the specific examples of the processhereinbefore given, and the specific illustrations of the process given in the drawings and in the flow sheet are illustrative of the invention, and that variations can be made in thefproportion of tar distilled and employed without distillation, in'the'particular'method of distillation employed, in the melting point of pitch produced and the yield of distillate oils, and in the proportionsin which the pitch and undistilled tar are blended, as well as variations in the character of cresote oil or other distillates produced, etc.

' The specific examples above described and illustrated on the drawings indicate the advantages of the invention when only a relatively small part of the tar produced is subjected to distillation and when the greater part of the tar is undistilled. Even in such cases pronounced advantages are obtained. Even greater advantages are obtained when larger proportions of the tar are distilled and greater yields of distillatev oils are produced and relatively smaller amounts of the new fuel composition are produced and used as fuel at the steel plant. The maximum advantages are obtained when the maximum amount of tar is distilled and only sufficient tar remains undistilled to blend with the pitch residue from the distillation to make the new fuel composition.

I claim:

1. The improvement inthe utilization of coke oven tar as fuel in steel plants which comprises subjecting part of the tar to distillation to give a distillate suitable for use for creosote oil and a pitch residue, blending the pitch residue while hot and thinly fluid from such distillation with coke oven tar with agitation to promote the formation of a uniform product, and supplying the resulting product in a hot and thinly fluid condition as fuel to the open hearth or other furnaces of the steel plant.

2. The improvement in the utilization of coke oven tar as fuel in steel plants which comprises subjecting part of the tar to distillation to give a distillate suitable for use for creosote oil and a pitch residue, blending the pitch residue while hot and thinly fluid from such distillation with coke oven tar by adding the tar and pitch to a previouslyblended and thinly fluid mixture thereof with agitation to promote the blending operation and supplying the resulting product in a hot and thinly fluid condition as fuel to the open hearth or other furnaces of the steel plant.

3. The improvement in the utilization of coke oven tar as fuel in steel plants which comprises subjecting part of the tar to distillation in a continuous manner to give continuously a distillate suitable for use for creosote oil and a pitch residue, blending the pitch residue produced by such continuous distillation with coke oven tar in a continuous manner by bringing the still hot and thinly fluid n pitch and tar together with agitation to promote the formation of a uniform product and supplying the resulting mixture in a hot and thinly fluid condition as fuel to the open hearth or other furnaces of the steel plant.

4. The further improvement in the process of claim 3 in which the continuous blending of the tar and pitch with each other is promoted by adding the still hot pitch and the tar continuouslyto a hot and thinly fluid previously blended mixture with continuous drawing off of the blended product and maintenance of a body thereof with which the continuously added tar and pitch are blended.

5. The improvement in the utilization of coke oven'tar as fuel in steel plants which comprises subjecting part of the tar to distillation to give a distillate suitable for use for creosote oil and a pitch residue having a melting point in excess of. about 250 F.,

blendin the pitch residue while still hot and thinly uid with coke oven tar with agitation to promote-the formation of a uniform prodnot, keeping the resulting mixture hot and thinly fluid and supplying it in a hot and thinly fluid condition as fuel to the open hearth or other furnaces of the steel plant.

' 6. The improvement in the utilization of coke oven tar as fuel in steel plants which comprises subjecting part of the tar to distillation to give a distillate suitable for use for creosote oil and a pitch residue having a melting point of about 300 F., blending the pitch residue while still hot and thinly fluid with coke oven tar with agitation to promote the formation of a uniform product, keeping the resulting mixture hot and thinly fluid and supplying it in a hot and thinly fluid condition as fuel to the furnaces of the steel plant.

7. The improvement in the utilization of excess coke oven tar at coke oven and steel plants where a part only of the tar is required as fuel in the steel plants which comprises subjecting the excess tar and part of the tar normallykrequired as fuel to jdistillation'to produce therefrom distillate oil suitable for 7 use for creosote oil anda pitch residue, blend:

ing thepitch residue while stillhot andthinlyfluid with tar to be used as fuel in the steel plant to form a homogeneous blended fuel, product and supplying such fuel product in a hot and thinly fluid condition to supplyt e fuel needs of the-furnaces of the'steel plant.

8. The improvementin the utilization of coke oven tar as fuel in steel plants where the coke oven tar is available in excess of the fuel requirements which comprises dividing thetar into two parts, the'first of which is less than the fuel requirements, distilling the second part of the tar to give a distillate oil suitable for use "ascreosote oil and a pitch residue, blending thepitch residue while stillhot and thinly fluid with the first part of the tar'to give a homogeneous and thinly fluid hot ,fuel mixture, and supplying such'tuel mixture in'a hot and thinly fluid condition to the furnaces of thesteel plant-.5

9. The improvementin the utilization of coke oven tarias fuel in steelplants where the coke oven tar is available in excess ofthe fuel requirements which compr1ses d1v1d1ng the tar into three parts,athe first of which is less than the fuel requirements, distilling a sec-.- ond part of such tar to give a distillate suitable for use for creosote oil and-a pitch residue inamount sufficient when blendedfwith o a suffici t xtent op oduce an oil suita le for. creosoting purposes and. a high ng poi pitch WM 1 W u d So i fife eled it!) ord a ytemp a u es, dr ng f the ho and thinly fluid pitch produced by the stil lation I and continuously blendingit, W le.

still in such a hot and thinly fluid condition,

pitchfresidue from'such distillation and con 7 tinually supplying'it, While in a still hotzand thinly fluid state from such distillation,- to a body of previously adniixedtar and pitch,

continuously and simultaneously supplyin to-said body unheatedtar, and agitatingsai dy P o b ding erew th @f the hot high l ng p n tpit h. a dof the 1 1- heated tar to promote the'formation gof'a uni formly bflended'pro'duet. -f In testimony whereof I 'aflix signature, TUA T A WLEE the first part of the tar to meet the fuel re quirements, blending such pitch while stillhot and thinly fluid with the tar. to iorm a thinly fluid mixture, and supplying such mix ture in a hot and thinly fluid condition as fuel to the furnaces of the steel plant.

1 0. The method of producing acomposite product from'coal tar,'which comprises sub;

jecting tar to distillation in a continuous manner to produce therefrom distillate oils and a pitch residue, drawing ofl' the pitch residue while it is hot and thinly fluid from.

the distillation and continuously blending it with coal tar in an unheated condition,"with agitation of the mixture to promote the for mation of auniform and thinly fluid blended product.

11. :The method of produeingia composite, product from coal tar, which comprises subjecting a portion of the tar to distillation in a contlnuous manner to produce therefromdistillate oils and a pitch residue, withdrawing the pitch'residue while in a hot and thinly fluid state from the distillation and c0ntinu- 'ously adding the same to a body of previously admixed hot pitch and tar, continuously adding unheatedtar to said body, and agitating said body to cause blending of the'addedhot pitch andunheated tar therewith.

12. The method of producing a composite product from coaltar, whichcomprises subjecting'partof the tar to distillation in a continuous mannerand carrying the distillation 

